A conventional display mechanism of an analogue quartz crystal wrist watch is composed as shown in FIG. 1.
An output from a motor composed of a stator 1, a coil 7 and a rotor 6 is transmitted to a fifth wheel and pinion 5, a fourth wheel and pinion 4, a third wheel and pinion 3, a second wheel and pinion 2, and thereafter the output is transmitted to a cannon pinion, a cannon wheel, a calendar mechanism though not shown to thereby drive a second wheel, a minute wheel, an hour wheel and a calendar. Though a load upon a stepping motor of a wrist watch is very small except when the calendar is advanced, for instance, the load of 1.0 g-cm torque is present in the case of a center wheel and pinion, however, twice as much torque is necessary in the case when the calendar is advanced. Accordingly, there is a problem that a power to stably drive the calendar mechanism is usually supplied though it takes no more than six hours to advance the calendar in 24 hours, by the reasons mentioned above. The circuit composition of the conventional electronic watch is shown in conjunction with FIG. 2.
A 32.768 KHz signal of an oscillating circuit 10 is transduced to a one second signal by a dividing circuit 11. The one second signal is transduced into a signal of 7.8 msec in width, with a 2 second period by a pulse width composing circuit 12 and is applied to inputs 15, 16 of inverters 13a, 13b, there is fed the signal of the same period and the same pulse width, whereby an inverted pulse, the direction of current flow of which changes each second is applied to a coil 14, and thereby the rotor 6, two poles of which are magnetized, magnetized rotates in one direction.
FIG. 3 shows a current wave form of the coil. Thus, the driving pulse width of the conventional electronic wrist watch is settled by taking a maximum torque as a standard, whereby the power is wasted during the time period which does not require a large torque and as a result a reduction of the electric power consumption is not realized.